There are many grades of bolts but the identification is on the head. For most applications use SAE grade 5 which has three lines on the head. For Metrick 8.8 is a good grade.
The length of a bolt is measure not including the head. For pitch you need a pitch gauge or use a tap and die set and compare.
There is a lot more involved in fasterners than this but if you have a particular application let me know and I can help.
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88 347, Twisted wedge heads,Comp Cams 224/230 cam, 1/4=10.523 @ 125.99, 60' = 1.472
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